code: def compute_optimal_reward(unused_observation):
      return tf.constant(10.0)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import parameterized
  import tensorflow
  from tf_agents.bandits.metrics import tf_metrics
  from tf_agents.bandits.policies import constraints
  from tf_agents.specs import tensor_spec
  from tf_agents.trajectories import time_step
  from tf_agents.trajectories import trajectory
label_desc: Use image node_id 1 for calling a global function with example usage: compute_optimal_reward(unused_observation) and returns: tf